San Francisco 49ers outside linebacker Aldon Smith (99) walks off the field after the second quarter against the Indianapolis Colts at Candlestick Park. / Kyle Terada, USA TODAY Sports

by Jorge L. Ortiz, USA TODAY Sports

by Jorge L. Ortiz, USA TODAY Sports

SAN FRANCISCO â?? The defending NFC champion San Francisco 49ers, who are off to a 1-2 start and have given up at least 27 points in each game, won't have the services of All-Pro linebacker Aldon Smith for an indefinite period.

Team owner Jed York said after Sunday's 27-7 loss to the Indianapolis Colts that Smith won't be with the team when it faces the St. Louis Rams on Thursday at the Edward Jones Dome. Smith was arrested on suspicion of driving under the influence Friday morning, but was kept on the active roster and played against the Colts.

While avoiding using the word "rehab,'' York strongly hinted that Smith would take a leave of absence to pursue counseling.

Asked why Smith was allowed to play, York said, "Our opinion was sitting somebody down and paying them to sit down when they're going to seek treatment in the future, that didn't seem like an appropriate punishment.''

York said repeatedly the 49ers would stand by Smith as long as he took steps to address his problem.

Smith briefly was jailed Friday and charged with DUI and marijuana possession after his pickup truck struck a tree in a single-vehicle accident around 7 a.m.

The arrest was the latest in a series of transgressions for the talented linebacker, who turns 24 on Wednesday.

In January 2012, Smith was arrested in Miami on DUI charges, although they were later reduced. In June of last year he was stabbed during a party at his house in San Jose. Earlier this month, Smith was named as defendant in two lawsuits from plaintiffs who say they were shot at that party.

Smith made a short statement to reporters and did not take questions.

"First off, I want to apologize to the team, the organization, my family, everybody I let down,'' he said. "I also wanted to let it be known this is a problem, and it's something I will get fixed. I'll try to do everything in my power to make sure this never happens again.''

Before being shut out by the Colts, Smith was off to another strong start with 3Â½ sacks in the first two games, including two in last Sunday's loss to the Seattle Seahawks. That gave him multiple sacks for the 10th time since 2011, the most in the NFL in that stretch.

Smith's total of 30Â½ sacks in 2011 and '12, including a franchise-record 19 Â½ last year, were the most ever for a player in his first two seasons since sacks became an official statistic in 1982.

Safety Donte Whitner said the arrest did not contribute to the 49ers losing their second game in a row, but he pointed out Smith had been subdued after the incident.

"He feels bad for what he did. I don't think you'll see another problem out of Aldon from this point on,'' Whitner said. "He hasn't really been himself, been a little quiet. He feels like he let everybody down. Hopefully he learned some lessons and gets it all together.''